4.8 References - Additional description or additional rules?

Following the reference syntax we say:

"References always begin with '['; this immediately disambiguates cell addresses from function names and named expressions. SheetNames include single-quote(') characters by doubling them and having the entire name surrounded by single-quotes. Column labels shall be in uppercase. The syntax above supports whole-row and whole-column references, but they shall always have a range marker, e.g. [.A:.A] would be a reference to the whole first column and [.1:.1] a reference to the whole first row of the current sheet. The optional "$" marking in sheet names, Column , and Row is used to identify absolute values; without the marking they are relative. "

1. With the exception of the requirement for references to always have a range marker, isn't this already stated in the syntax?

2. With reference to the range marker, why isn't that reflected in the syntax?

3. I am not sure what "The optional "$" marking in sheet names, Column , and Row is used to identify absolute values; without the marking they are relative." may mean. If it is an absolute value, then it isn't relative. Yes? Or is there some other meaning at work here?